Automatic machine for applying handles to filled hypodermic syringes



March 31, 1970 J. B. LAGSDIN 3,

AUTOMATIC MACHINE FOR APPLYING HANDLES TO FILLED HYPODERMIC SYRINGESFiled Jan. 11, 1968 5 Sheets-Sheet l INVENTOR. JUL/U5 BERNARD LAG'SD/NATTORNEY March 31, 1970 J. B. LAGSDlN 3,503,113

AUTOMATIC MACHINE'FOR APPLYING HANDLES TO FILLED HYPODERMIC SYRINGESFiled Jan. 11, 1968 5 Sheets-Sheet z Hg-VENTOR. JUL/US BERNARD EA GSD/NA TTORNEY March 31, 1970 J. B. LAGSDIN 3,503,113

- AUTOMATIC MACHINE FOR APPLYING HANDLES 'TO FILLED HYPODERMIC SYRINGES5 Sheets-Sheet- 5 Filed Jan. 11, 1968 ,lNVENTOR. JUL/U5 BERNARD LAGSDl/VATTORNEY Maroh31, 1970 J.B.LA-sD|N 3,503,113

AUTOMATIC MACHINE FOR APPLYING HANDLES TO FILLED HYPODERMIC SYRINGESFiled Jan. 11, 19 68 m R JUL/US BER/VA P0 LAGSD/N N ATTORNEY 5Sheets-Sheet 4.

INVENTOR.

March 31, 1970 B, LAG 3,503,113

AUTOMATIC MACHINE FOR APPLYING HANDLES TO FILLED HYPODERMIC SYRINGESFiled Jan. 11, 1968 5 Sheets-Sheet 5 INVENTOR. JUL/US BERNARD.-LAG'SDl/V kz Ww ATTORNEY United States Ratent O 3,503,113 AUTOMATICMACHINE FOR APPLYING HAN- DLES T FILLED HYPODERMIC SYRINGES JuliusBernard Lagsdin, Pearl River, N.Y., assignor t American CyanamidCompany, Stamford, Conn., a

corporation of Maine Filed Jan. 11, 1968, Ser. No. 697,096 Int. Cl.B2313 19/04 US. Cl. 29-208 3 Claims ABSTRACT OF THE DISCLOSURE Threadedhandles are applied on semi-automatic machinery to threaded stoppers ina filled hypodermic syringe to form a plunger. The machine has a seriesof cylinders of suitable size to receive the barrels of the syringes.These cylinders are provided at the top with soft gaskets of elastomerto grip the syringe barrel. Handles for the syringes, provided with ribsto prevent turning, are then dropped into syringe barrels inserted inthe cylinders of the machine. Guide plates with suitable holes guide thehandles as they are inserted. Movable locking plates adjacent to thecylinder handles are swung into position and prevent turning of thehandles when the cylinders turn. The threaded handles are inserted, andthen a second bar having rods aligned to contact the top of the handlesis lowered. The rods are provided with light springs so that whenlowered they press against the handles with a light, predeterminedpressure. The cylinders are then rotated in the proper direction toscrew the threaded handles into the threaded stoppers. The light springpressure assures that there is sufiicient pressure to screw in thehandles but insufiicient pressure to cause the stopper to move and thusdischarge part of the contents of the syringe. The soft elastomergaskets around the tops of the cylinders grip the syringe barrelssufiiciently so that the barrels are turned when the cylinders turn.

BACKGROUND OF THE INVENTION Disposable hypodermic syringes areextensively used today. These syringes are filled with a predeterminedvolume of liquid and then an elastic stopper with female threads isdropped down onto the surface of the liquid. Finally, handles havingcooperating male threads are inserted into the syringe barrels and thenare screwed into the female threads of the stopper, thus forming aunitary plunger.

Problems are presented by the fact that when the handles are insertedand screwed in by hand, as was the practice hitherto, the operation isslow and production outputs are limited. An even more important problemis presented by the fact that there is a relatively narrow range ofpressure which can be applied to the handles while they are beingscrewed in. A certain minimum is needed to assure that the threadscatch, but if there is too much pressure, the rubber stopper can bemoved down, which causes some of the liquid in the syringe to beexpelled, thus changing the dosage and creating other problems. As aresult, a number of rejects are produced, particularly near the end ofthe day when the operator is tired, and this of course is economicallyhighly undesirable.

SUMMARY OF THE INVENTION The present invention provides an automaticmachine which screws in handles in a large number of syringessimultaneously and provides an accurate, predetermined, gentle pressurewhich is sufiicient to cause the threads to catch but insufiicient tomove the stoppers. As a result,

output is speeded up and rejects are substantially eliminated.

The machine is provided with a number of cylinders of suitable size totake the barrels of syringes with the needle down. The tops of thecylinders have a gasket of elastic material, such as rubber, so thatwhen the cylinders are turned the barrels turn with them but thefriction is light so that when the handles are fully screwed into thestoppers the cylinders can slip for a short distance. in other words,the light friction of the rubber gaskets operate as a weak clutch,holding only sufficiently so that the syringe barrels are turned whilethe handles screw into the stoppers.

A second bar is then lowered with rods aligned to strike the handles,and each rod is provided with a predetermined light spring which exertsa definite and accurate light pressure on the top of the handles. Thecylinders are then started to rotate, turning the barrels in the proeprdirection to screw the threaded handles into the stoppers. When thehandles have been seated, the cylinders stop turning, the bars areraised, the syringes removed, and the operation repeated.

In order to speed up operations, the syringe barrels are mounted inholes in a carrier tray so that a number can be introduced into thecylinders at the same time.

As it takes no longer to screw in handles in a large number of syringessimultaneously than it does to screw one in by hand, great increase inproduction output is made possible. At the same time, the springpressure is accurately predetermined so that it is just right to holdthe handles sufliciently so that the threads will catch but is not greatenough to move the stoppers in the barrels. After introduction of thehandles the bar carrying the rods can be lowered manually or theactuation can be effected mechanically, for example pneumatic actuation.The exact method by which the bars are moved does not, strictlyspeaking, form any part of the present invention, but because of thesimplicity of actuation, pneumatic means are preferred and will bedescribed in the more specific description below; but of course theinvention is not limited in its broader aspects to pneumatic actuationof the bars or to any other particular method of bringing them intoposition.

The cylinders and the carrier trays can readily be changed toaccommodate different sizes of syringes. This adds a desirableflexibility and versatility to the machine and constitutes a practicaloperating advantage. Obviously of course, if the machine is to be usedfor only one syringe size, the cylinders may be mounted morepermanently. However, as it is quite simple to change cylinders andlocking bars, it is normally desirable to use this modification eventhough changes in syringe size may not be immediately contemplated.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a section through adisposable syringe with the handle separated from the stopper;

FIGURE 2 is a front elevation, partly broken away, of a machine beforeintroducing syringes;

FIGURE 3 is a similar elevation, but not broken away, of the samemachine with syringe barrels introduced into the cylinders, lockingplates applied, and some of the handles introduced;

FIGURE 4 is a similar front elevation with the bar containing springpressed rods lowered into contact with the handles;

FIGURE 5 is a side elevation, partly in section, showing pneumaticactuation of the bar carrying rods; and

FIGURE 6 is a detail plan view of a handle and the two locking platesfor preventing turning.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGURE 1 shows a typicalsyringe and as such may represent the prior art. The syringe has abarrel 1 partly filled with the liquid 2 and, of couse, the conventionalneedle 3. On top of the liquid in the barrel there is placed a stopper4, for example of rubber, provided with internal female threads 5. Thebarrel has the customary finger grips 6 and a handle 24 with ribs 7 isshown inserted but not quite touching the stopper 4. This handle isprovided with male threads 8. In the figure the ribs are shown with onepair in the plane of the paper for clarity, actually FIGURE 1 representsa handle which is positioned about 45 from the actual position in themachine as can be seen from FIGURE 6. From the latter figure it isapparent that the ribs must be oriented so that they extend at an anglesomewhere in the neighborhood of 45 to the locking plates 17 whichengage the ribs and prevent any substantial turning of the handle afterthe ribs strike the locking plate 17.

Turning to FIGURES 2 and it will be seen that the machine is providedwith a top plate 9, a front plate 10, and a series of cylinders 11 whichpass through openings in the top plate and are fastened to shafts 12turned through the bevel gears 13 by the motor 14. The cylinders aredetachably mounted on their shafts and carry at their tops a ring ofelastic material 15. For economy of space, shafts 12 of each pair ofcylinders are turned from a single spur gear 25 meshing with two smallspur gears 26 on the end of each shaft. The gears 25 are in turn mountedon short stub shafts 27 each of which is driven by a bevel gear 13.

FIGURE 3 shows the same machine as in FIGURE 2 with a series of syringebarrels 1 inserted in the cylinders. The barrels are held in openings ina plate 16 which forms part of a tray provided with an additional upperplate 28 having guide holes 19 through which handles are inserted intothe barrels as will be described below. The whole tray is hung onto theframework with a short channel section 29. This can best be seen inFIGURE 3 which shows only two openings 19 in order not to confuse thedrawings, one handle is shown moving through an opening 19 and a secondhandle just before introducting into another hole 19. This secondhandle, as in FIGURE 1, is shown with the rib 7 in the same position asin FIGURE 1 for clarity. Of course before the handle is inserted it isslightly turned so that the ribs 7 can pass between locking plates aswill be described below. Exact orientation is not necessary whichpermits rapid operation because even if the ribs are not perfectly inposition when cylinders start to turn the barrel the handles will turnslightly until a rib encounters a locking plate which will be described.

FIGURE 2 shows a pair of locking plates 17 fastened to shafts 36 whichare turned by knurled knobs 31. In their raised position the lockingplates permit removing a tray of syringes with handles inserted and alsoinserting a fresh tray containing the barrels as has been describedabove. The knurled knobs are then turned bringing the two locking plates17 close to the ribs 7, as is best seen in FIGURE 5 although FIGURES 3and 4 also show one locking plate 17 in the closed position. FIGURES 6,of course, also shows the plates in the closed or locking position andthis figure shows why the plates lock the ribbed handles and keep themfrom turning.

FIGURE 4 shows a bar 20 lowered by the pneumatic cylinder 23. FIGURE 5illustrates the operation of the pneumatic cylinder which moves links32, pivoted in the framework, and which cause the bar 20 to be raised orlowered. In FIGURE 5 the lowered position is shown in full lines and theraised position in dashed lines. The bar 23 is provided with a series ofrods 21 which are urged against the tops of the handles by light,predetermined spring pressure. The bar is shown broken away at one endto illustrate a spring 22. The structure is also shown in section inFIGURE 5 and it will be apparent that the rods can move only a certaindistance before their flanges 33 strike shoulders 34. In FIGURE 4 therods 21 are shown almost striking the shoulders 34.

After both bars are in place, as is shown in FIGURE 4, the motor isstarted and all of the cylinders turn in the proper direction, screwingthe threaded handles into the rubber stoppers. As the pressure by thespring 22 is accurately predetermined and is too slight to move thestoppers, no liquid escapes. However, the pressure is suflicient to urgethe threaded ends of the handles into the recesses in the stoppers sothat the handles are reliably screwed into each stopper. As thecylinders start turning and the handles screw into the stopper the firstsmall motion brings the rods 21 down until the collars 33 strike theshoulders 34. Thereafter as a handle screws in there is no springpressure on it. Of course, by the time the handle has been screwed inall the way there will be a slight gap between the end of each rod 21and the top of its corresponding syringe handle. However, as FIGURE 4shows the position just before the cylinders start turning, no gapappears on this figure.

As has been mentioned above, when the handles are screwed in all the waythe friction of the barrels 1 against the stoppers 4 is much greaterthan between the elastic collar of each cylinder and the syringe barrelpermitting a little slip, because at this point there is no springpressure and the barrels are held against the elastic gaskets 15 only bytheir small weight. The very slight slippage when the handle is entirelyscrewed in, which may be a very small fraction of a turn, is provided toassure that all handles are screwed in completely.

After the handles are all screwed in, the motor is shut off, thepneumatic cylinder is actuated, which raises bar 20, the knobs 31 arethen turned to raise the locking plates 17 to the position shown inFIGURE 2 which permits removing the set of syringes. A new set is thenintroduced into the cylinders, the operations then being repeated.

If it is desired to operate with a different size of syringe, thecylinders are detached and replaced with other cylinders of the propersize. The operation of the machine is, of course, the same as has beendescribed above.

What is claimed is:

1. An apparatus for automatically screwing in handles in disposablehypodermic syringes" which have been filled with a dose of liquid andprovided with resilient stoppers having a threaded central recessengaging a threaded end on the handles, comprising in combination,

(a) a housing having an upper plate,

(b) a series of cylinders on said plate and having projectionstherethrough, the cylinders having an internal diameter corresponding tothe external diameter of syringe barrels, and a resilient ring at thetop of each cylinder capable of gripping a syringe barrel,

(c) means for rotating the cylinders in a direction to screw syringebarrels containing a stopper onto threaded handles,

((1) a movable locking bar fitting over the syringes in thecylinders,said bar having openings of size suf ficient to permit introducingthreaded handles therethrough and being aligned over the cylinders,whereby when the locking bar is in contact with syringe barrels in thecylinders, threaded handles can be introduced through the openings inaccurate alignment with the barrels,

(e) a vertically movable bar provided with movable rods engageable withhandles in each syringe when 5 6 the bar is lowered, the rods beingunder predeterresilient pressure of the rods is provided by individualmined, light, resilient pressure suflicient to hold a springs. handle incontact with a stopper but insufiicient to References Cited move astopper in the syringe barrel, whereby when UNITED STATES PATENTS thecylinders are rotated the barrels of each syringe 5 3353 254 11/1967Ford 29240 are rotated therewith and the stoppers screwed onto thethreaded ends of the handles. 3,359,619 12/ 1967 W n 2 2. An apparatusaccording to claim 1 provided with THOMAS EAGER, Primary Examinerpneumatic actuating means for moving the two bars. U5, C1,X R

3. An apparatus according to claim 2 in which the 10 29 -24()

